Safe to delete 'other' files from storage?

Today I checked my computer's storage use and found that 31 gigs are being used by 'other'. Whoa. So I dug around until I found which files those were, and found that they were either photos (ones already in my camera roll backed up by the cloud) or files in my documents folder (also backed up in icloud). Is it safe to trash those files on my desktop, or will it eat the ones in the cloud too? Or are they duplicates? Thanks!